The loop antenna with a cylindrical core: Theory and experiment

The electromagnetic field of an electrically small loop antenna with a cylindrical core is investigated. The infinitely long cylinder may be conducting or insulating. With the help of the principle of similitude, measurements made with a small loop at a high frequency with cylinders of water with widely different conductivities are applied to a very large loop around a mountain at a very low frequency. An approximate equivalent circuit for the loop with a core is described and tested.